One Way ANOVA is used to determine whether varying the levels or values of a single factor affect a process. The following data show the strength of a fibre with varying percentages of a synthetic material:

1

2

3

4

5

15%

8 .7

9.8

12.2

12.9

9.5

20%

14.5

17.3

14.9

15.5

12.7

25%

16.0

13.8

18.3

17.2

18.0

30%

23.8

21.5

18.3

24.3

22.9

35%

9.0

14.3

10.0

14.3

7.1

An ANOVA analysis tests the hypothesis:
H_{0} The fibres are all of equal strength
H_{1} At least one of the fibres is of different strength
The analysis is:
Source of Variation

Sum of Squares

Degrees of Freedom

Mean Square

F_{0}

pvalue 
Factor

448.32

4

112.08

21.78

0

Error

102.91

20

5.15



Total

551.23

24




The alternative hypothesis is accepted, at least one of the fibres has a different mean strength.
